Journal ArticleDOI
Integrated chronostratigraphic calibration of the Oligocene-Miocene boundary at 24.0 ± 0.1 Ma from the CRP-2A drill core, Ross Sea, Antarctica
Gary S. Wilson,M. Lavelle,William C. McIntosh,Andrew P. Roberts,David M. Harwood,David K. Watkins,Giuliana Villa,Steven M Bohaty,Christopher R. Fielding,Fabio Florindo,Leonardo Sagnotti,Tim R Naish,Reed P. Scherer,Kenneth L. Verosub +13 more
TLDR
In this paper, an expanded Oligocene-Miocene boundary interval recovered in the Cape Roberts Project CRP-2A core from beneath the Ross Sea, Antarctica, has yielded a high-resolution integrated chrono stratigraphy that has, in turn, enabled a new, more direct, calibra tion of magnetic polarity and biostratigraphic events.Abstract:
An expanded Oligocene-Miocene boundary interval recovered in the Cape Roberts Project CRP-2A core from beneath the Ross Sea, Antarctica, has yielded a high-resolution integrated chrono stratigraphy that has, in turn, enabled a new, more direct, calibra tion of magnetic polarity and biostratigraphic events. The Oligocene-Miocene boundary interval in the CRP-2A core comprises three ∼60-m-thick, rapidly deposited (>0.5 m/k.y.) sedimentary sequences (sequences 9, 10, and 11). In sequences 10 and 11, single-crystal, laser-fusion 40Ar/39Ar analyses of anorthoclase phenocrysts from two tephra horizons independently calibrate the CRP-2A magnetic-polarity stratigraphy and age model. Sequences 10 and 11 encompass subchron C6Cn.3n, which is dated as 24.3 ± 0.1 to 24.16 ± 0.1 Ma. Sequence 9 is interpreted to encompass subchron C6Cn.2n and the Oligocene-Miocene boundary, which is dated as 24.0 ± 0.1 Ma. These ages are ∼0.2 m.y. older than those of the geomagnetic polarity time scale calibrated from seafloor-spreading ridges and ∼0.9–1.3 m.y. older than the newly proposed astronomically calibrated ages. We contend that the discrepancy with the astronomically calibrated ages arises from a mismatch of three 406 k.y. eccentricity cycles or a 1.2 m.y. modulation of obliquity amplitude in the astronomical calibration of the Oligocene–Miocene time scale.read more
Citations
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Journal ArticleDOI
Integrated chronostratigraphic calibration of the Oligocene-Miocene boundary at 24.0 ± 0.1 Ma from the CRP-2A drill core, Ross Sea, Antarctica COMMENT
TL;DR: Wilson et al. as discussed by the authors used 40Ar/39Ar data from the Cape Roberts Project CRP-2A core to assign absolute ages to polarity chrons in the vicinity of the Oligocene-Miocene (O-M) boundary, and estimate an age of 24.0 Ma for the O-M boundary.
Journal ArticleDOI
High-resolution evidence for dynamic transitional geomagnetic field behaviour from a Miocene reversal, McMurdo Sound, Ross Sea, Antarctica
Andrew P. Roberts,Anisch Bakrania,Fabio Florindo,Fabio Florindo,Christopher J. Rowan,Christopher R. Fielding,Ross D. Powell +6 more
TL;DR: This article reported a high-resolution record of a Miocene polarity transition from glacimarine sediments in McMurdo Sound, Ross Sea, Antarctica, which is the first transition record reported from high southern latitudes.
Miocene glacial dynamics recorded by variations in magnetic properties in the ANDRILL-2A drill core
Luigi Jovane,Luigi Jovane,Fabio Florindo,Fabio Florindo,Gary D Acton,Christian Ohneiser,Leonardo Sagnotti,Eleonora Strada,Kenneth L. Verosub,Gary S. Wilson,Francesco Iacoviello,Francesco Iacoviello,Richard H. Levy,Sandra Passchier +13 more
TL;DR: Jovane et al. as mentioned in this paper investigated the role of ocean discovery programs in the discovery of ocean skeletons and proposed a method for the extraction of skeletons from the seafloor.
Book ChapterDOI
Antarctic Ice Sheet dynamics during the Late Oligocene and Early Miocene: climatic conundrums revisited
TL;DR: The Oligocene-Miocene transition (OMT) is one of the most enigmatic periods in Earth's Cenozoic climate history as discussed by the authors , characterised in deep-sea benthic foraminiferal (δ18O) records by an increase of up to + 1 ǫ spanning a 200-300 kyr interval associated with global cooling and growth in Antarctic ice volume to as much as 120% of present day (Mi-1 glaciation).
Dissertation
Evolution of the Antarctic Peninsula continental margin from Late Eocene to present: Seismic stratigraphic analysis related to the development of the Antarctic Peninsula Ice Sheet (APIS)
TL;DR: Smith et al. as mentioned in this paper investigated the Antarctic Peninsula Ice Sheet (APIS) development from the stratigraphic record of three geographic areas: the James Ross Basin, NW Weddell Sea continental shelf, and the Joinville Slope.
References
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Journal ArticleDOI
Revised calibration of the geomagnetic polarity timescale for the Late Cretaceous and Cenozoic
Steven C. Cande,Dennis V. Kent +1 more
TL;DR: An adjusted geomagnetic reversal chronology for the Late Cretaceous and Cenozoic is presented that is consistent with astrochronology in the Pleistocene and Pliocene and with a new timescale for the Mesozoic.
Book ChapterDOI
A revised Cenozoic geochronology and chronostratigraphy
TL;DR: Cande and Kent as mentioned in this paper presented a revised (integrated magnetobiochronologic) Cenozoic time scale (IMBTS) based on an assessment and integration of data from several sources.
Journal ArticleDOI
Least squares fitting of a straight line with correlated errors
TL;DR: In this paper, the fitting of a straight line when both variables are subject to crrors is generalized to allow for correlation of the z and y errors, illustrated by reference to lead isochron fitting.
Journal ArticleDOI
A new geomagnetic polarity time scale for the Late Cretaceous and Cenozoic
Steven C. Cande,Dennis V. Kent +1 more
TL;DR: In this article, the relative widths of the magnetic polarity intervals for the entire Late Cretaceous and Cenozoic have been systematically determined from magnetic profiles from the world's ocean basins.
Journal ArticleDOI
Strontium Isotope Stratigraphy: LOWESS Version 3: Best Fit to the Marine Sr‐Isotope Curve for 0–509 Ma and Accompanying Look‐up Table for Deriving Numerical Age
TL;DR: An improved and updated version of the statistical LOWESS fit to the marine 87Sr/86Sr record and a revised look-up table (V3:10/99; available from jmcarthur@ucl.ac.uk) is presented in this article.
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